"He said there is going to be retribution like ISIS hasn't seen," said Republican Rep. Duncan Hunter Jr., a Marine Corps veteran of two tours in Iraq and one in Afghanistan, who was in the meeting with the king. "He mentioned 'Unforgiven' and he mentioned Clint Eastwood, and he actually quoted a part of the movie."

Hunter would not say which part of "Unforgiven" the king quoted, but noted it was where Eastwood's character describes how he is going to deliver his retribution. There is a scene in the picture in which Eastwood's character, William Munny, says, "Any man I see out there, I'm gonna kill him. Any son of a bitch takes a shot at me, I'm not only going to kill him, I'm going to kill his wife and all his friends and burn his damn house down."

Beyond airstrikes, Jordan could further contribute to the fight against ISIS through the use of its extremely effective special forces units.